Five-path three-electrode electrochemical luminescence detector

Abstract

The utility model discloses a five-way three-electrode electrochemiluminescence detector, which comprises an electrochemiluminescence chip and a constant potential excitation device, the electrochemiluminescence chip comprises an electrode plate and a sample adding plate, the front side of the electrode plate is provided with a shared counter electrode, a first working electrode, a first reference electrode, a second working electrode and a second reference electrode, a driving electrode of the shared counter electrode is arranged on the back surface of the electrode plate, the shared counter electrode is connected with the driving electrode, and the sample adding plate covers the shared counter electrode, the first working electrode, the first reference electrode, the second working electrode and the second reference electrode; the bottom ends of the first working electrode, the first reference electrode, the second working electrode and the second reference electrode and the bottom end of the driving electrode are used as electric contact areas, and sample adding sheets corresponding to the shared counter electrode, the first working electrode and the first reference electrode or the second working electrode and the second reference electrode form a first reaction tank and a second reaction tank; the constant potential excitation device is connected with the electric contact area to excite the first reaction tank and the second reaction tank to generate electrochemical luminescence reaction.

Description

Technical Field

[0001] This utility model relates to the field of electrochemiluminescence detection technology, and more specifically, to a five-channel three-electrode electrochemiluminescence detector. Background Technology

[0002] Electrochemiluminescence (ECL) technology, as an analytical method with high sensitivity and selectivity, has been widely used in biomedicine, environmental monitoring, food safety, and other fields. An ECL detection system typically consists of a detection unit, an excitation unit, a photoelectric detection unit, and a data processing unit. In a traditional three-electrode ECL detection system, the detection unit usually includes a working electrode, a reference electrode, and a counter electrode; the excitation unit controls the potential between the reference electrode and the working electrode to maintain a relatively constant potential, thereby driving the electrochemiluminescence reaction on the surface of the working electrode.

[0003] Traditional three-electrode electrochemiluminescence detection systems exhibit good performance in single-cell systems, but face numerous challenges in dual-cell systems. Currently, a three-electrode electrochemiluminescence sensor exists, based on a shared working electrode, reference electrode, and counter electrode. Its detection and control regions (i.e., the two reaction cells) are integrated on the chip surface in a parallel structure. During electrochemical excitation, the two reaction cells share a single negative feedback control loop composed of the working and reference electrodes, and the current supplied by the excitation unit to the two reaction cells must flow through the same working electrode.

[0004] This excitation method restricts the current distribution between the two reaction cells to a shared working electrode, preventing independent current control. This current coupling effect leads to mutual interference between the electrochemical processes in the two reaction cells, thus affecting the stability and controllability of the detection system. Currently, there is a portable electrochemical excitation device employing a traditional three-electrode system (working electrode, reference electrode, and counter electrode) potentiostat architecture. When this device is used to excite electrochemiluminescence in a dual-reaction cell, the two reaction cells in the detection unit must share a single potentiostat. This shared architecture cannot achieve independent potential control between the reference and working electrodes of each reaction cell, resulting in intensified electrode polarization and ultimately a decrease in detection sensitivity. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a five-channel three-electrode electrochemiluminescence detector. In the case of sharing a counter electrode, it has a negative feedback loop composed of two completely independent reference electrodes and working electrodes. The potential between the reference electrode and the working electrode constituting the loop can be independently controlled, the current of the two reaction cells can be independently adjusted, and the two reaction cells can independently carry out electrochemiluminescence reactions.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A five-channel three-electrode electrochemiluminescence detector includes an electrochemiluminescence chip and a constant potential excitation device. The electrochemiluminescence chip includes an electrode sheet, a sample application sheet, an upper cover, and a lower cover. The electrode sheet and the sample application sheet are disposed between the upper cover and the lower cover. The front side of the electrode sheet is provided with a shared counter electrode, a first working electrode, a first reference electrode, a second working electrode, and a second reference electrode. The back side of the electrode sheet is provided with a driving electrode for the shared counter electrode. The shared counter electrode is connected to the driving electrode. The sample application sheet covers the shared counter electrode, the first working electrode, the first reference electrode, the second working electrode, and the second reference electrode.

[0008] The bottom ends of the first working electrode, the first reference electrode, the second working electrode, the second reference electrode, and the driving electrode serve as electrical contact areas. They share the first side of the counter electrode, the first side of the sample application sheet corresponding to the first working electrode and the first reference electrode to form a first reaction cell. They share the second side of the counter electrode, the second side of the sample application sheet corresponding to the second working electrode and the second reference electrode to form a second reaction cell. A constant potential excitation device is connected to the electrical contact areas to excite the first and second reaction cells to produce an electrochemiluminescence reaction.

[0009] The constant potential excitation device includes a power supply unit, a constant potential circuit, an external interface circuit, a WiFi circuit, a control unit, a relay circuit, an OLED display, a reset circuit, a serial port circuit, a signal generation circuit, and a button circuit integrated on a circuit board. The constant potential circuit, external interface circuit, WiFi circuit, control unit, relay circuit, OLED display, reset circuit, serial port circuit, signal generation circuit, and button circuit are respectively connected to the power supply unit. The constant potential circuit, external interface circuit, WiFi circuit, relay circuit, OLED display, reset circuit, serial port circuit, signal generation circuit, and button circuit are respectively connected to the control unit. The signal generation circuit is connected to the constant potential circuit. The power supply unit is connected to an external power supply.

[0010] Furthermore, the power supply unit includes a +5V to +3.3V step-down circuit, a +5V to +12V boost circuit, a +5V to -12V step-down circuit, a +12V to +5V step-down circuit, and a +12V to +5.21V step-down circuit. The +5V to +3.3V step-down circuit provides power to the control unit, relay circuit, signal generation circuit, OLED display, serial port circuit, and WiFi circuit.

[0011] The +5V to +12V boost circuit provides power to the signal generation circuit and the constant potential circuit, and also provides power to the +12V to +5V buck circuit and the +12V to +5.21V buck circuit; the +5V to -12V buck circuit provides power to the signal generation circuit and the constant potential circuit, and the +12V to +5V buck circuit and the +12V to +5.21V buck circuit provide power to the signal generation circuit.

[0012] Furthermore, the +5V to +3.3V step-down circuit uses the AMS1117-3.3 linear regulator chip to convert the external +5V power supply voltage to +3.3V voltage. The +3.3V voltage is used for current limiting through a 4.7KΩ resistor to drive the indicator light to show the circuit's operating status. The circuit is configured with 22μF and 100nF decoupling capacitors for filtering.

[0013] Furthermore, the +5V to +12V boost circuit uses the DC-DC converter chip MT3608 to boost the external +5V power supply. The boosted voltage signal is converted into a +12V output signal using a linear regulator 78L12. The +12V output signal is isolated into an analog +12V voltage signal and a digital +12V voltage signal through a 0Ω resistor. The analog +12V voltage signal provides positive power to the signal generation circuit and the constant potential circuit, while the digital +12V voltage signal provides positive power to the +12V to +5V buck circuit and the +12V to +5.21V buck circuit.

[0014] The +5V to -12V step-down circuit uses an asynchronous step-down converter HT7463A to convert the external +5V power supply into a negative voltage signal. The negative voltage signal is then converted into a -12V output signal using a linear regulator 79L12. The -12V output signal is isolated into an analog -12V voltage signal and a digital -12V voltage signal through a 0Ω resistor. The analog -12V voltage signal provides negative power to the signal generation circuit and the constant potential circuit.

[0015] Furthermore, the +12V to +5V step-down circuit converts the digital +12V voltage signal into a 5V voltage through the voltage reference chip REF195GSZ, providing a regulated power supply for the signal generation circuit.

[0016] The +12V to +5.21V step-down circuit uses a linear regulator LM317LF to convert the digital +12V voltage signal to +5.21V. The +5.21V voltage drives the LED9 indicator light to illuminate and indicate the circuit's operating status through a 10KΩ resistor for current limiting.

[0017] Furthermore, the external interface circuit includes a +3.3V interface, a +12V interface, a -12V interface, a +5V interface, a +5.21V interface, a shared counter electrode interface, a first working electrode interface, a first reference electrode interface, a second working electrode interface, and a second reference electrode interface.

[0018] The +3.3V interface is connected to the output of the +5V to +3.3V step-down circuit; the +12V interface is connected to the output of the +5V to +12V boost circuit; the -12V interface is connected to the output of the +5V to -12V step-down circuit; the +5V interface is connected to the output of the +12V to +5V step-down circuit; and the +5.21V interface is connected to the output of the +12V to +5.21V step-down circuit. The shared counter electrode interface, first working electrode interface, first reference electrode interface, second working electrode interface, and second reference electrode interface are respectively connected to the drive electrode, first working electrode, first reference electrode, second working electrode, and second reference electrode.

[0019] Furthermore, the constant potential circuit includes two voltage followers OPA604, an operational amplifier OP07, and a power amplifier BUF634. The two voltage followers OPA604 are used to maintain a constant potential between the first reference electrode and the first working electrode or between the second reference electrode and the second working electrode. The operational amplifier OP07 provides an excitation signal for the shared counter electrode, and the power amplifier BUF634 amplifies the excitation signal output by the operational amplifier OP07 again.

[0020] Furthermore, the control unit includes an STM32F103CBT6 chip, a clock circuit, a startup circuit, and a decoupling circuit. The clock circuit uses a crystal oscillator to provide the running clock signal to the STM32F103CBT6 chip, and capacitors are connected across the two ends of the crystal oscillator for filtering. The startup circuit uses pin headers connected in series with resistors to the BOOT0 and BOOT1 pins of the STM32F103CBT6 chip. The decoupling circuit uses multiple capacitors to connect the 3.3V supply voltage to the ground terminal of the STM32F103CBT6 chip.

[0021] Furthermore, the serial port circuit uses a USB to TTL serial port chip, the reset circuit uses a low-level reset method, the relay circuit uses NPN transistors and PNP transistors as switches, and the OLED display screen is used to display the status of the constant potential excitation device and the excitation voltage value.

[0022] Furthermore, the signal generation circuit includes a digital-to-analog converter chip DAC8831 and an operational amplifier OPA277. The digital signal output by the microcontroller is converted into an analog signal by the digital-to-analog converter chip DAC8831 and the operational amplifier OPA277 and then sent to the constant potential circuit.

[0023] Compared with existing technologies, this invention, while sharing a counter electrode, features a negative feedback loop composed of two completely independent reference electrodes and working electrodes. The potential between the reference and working electrodes forming the loop can be independently controlled, and the current in the two reaction cells can be independently adjusted. This avoids mutual interference between the electrochemical reactions in the two reaction cells, allowing each cell to independently undergo electrochemiluminescence reactions. This invention can simultaneously excite reactants in the same or different systems, expanding the application range of the three-electrode electrochemiluminescence detector in the field of electrochemiluminescence detection and improving detection efficiency.

[0024] The constant potential excitation device of this invention adopts a triggering mechanism that first connects to the reference electrode and working electrode on the electrochemiluminescence chip, and then connects to the shared counter electrode. This overcomes the situation where the working electrode and counter electrode form two-electrode electrochemiluminescence first when the excitation device is connected to three electrodes at the same time. This significantly improves the controllability of the electrochemiluminescence reaction triggering and provides more stable and accurate constant potential control for electrochemiluminescence detection.

[0025] This invention's constant potential excitation device allows for setting timing current method parameters via a host computer, resulting in simple operation and low cost. It achieves dual control through both the button circuit's button terminal and the host computer terminal, supporting both wired and wireless control methods, providing a flexible and diversified control solution. Furthermore, this invention employs a low-power circuit design and simplified operation process, reducing maintenance costs and complexity, making it suitable for long-term continuous operation, especially for applications requiring continuous electrochemiluminescence detection. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an electrochemiluminescence chip.

[0027] Figure 2 This is a schematic diagram of the electrode sheet and the sample sheet.

[0028] Figure 3 This is a schematic diagram of the upper cover.

[0029] Figure 4 This is a schematic diagram of the lower cover.

[0030] Figure 5 This is a block diagram showing the connections between the various modules on the circuit board.

[0031] Figure 6 This is a schematic diagram of a +5V to +3.3V power supply unit circuit.

[0032] Figure 7 This is a schematic diagram of a +5V to +12V power supply unit circuit.

[0033] Figure 8This is a schematic diagram of a +5V to -12V power supply unit circuit.

[0034] Figure 9 This is a schematic diagram of a +12V to +5V power supply unit circuit.

[0035] Figure 10 This is a schematic diagram of a +12V to +5.21V power supply unit circuit.

[0036] Figure 11 This is a schematic diagram of a constant potential circuit.

[0037] Figure 12 This is a schematic diagram of the external interface circuit.

[0038] Figure 13 This is a schematic diagram of a WiFi circuit.

[0039] Figure 14 This is a schematic diagram of the control unit circuit.

[0040] Figure 15 This is a schematic diagram of a relay circuit.

[0041] Figure 16 This is a schematic diagram of an OLED display circuit.

[0042] Figure 17 This is a schematic diagram of the reset circuit.

[0043] Figure 18 This is a schematic diagram of a serial port circuit.

[0044] Figure 19 This is a schematic diagram of a signal generation circuit.

[0045] Figure 20 This is a schematic diagram of the button circuit.

[0046] Figure 21 The graph shows the linear fit between hydrogen peroxide concentration and ECL luminescence intensity.

[0047] Figure 22 This diagram illustrates the simultaneous and individual stimulation of the first and second reaction cells.

[0048] Figure 23 This is a comparison of the ECL signal intensity in the first and second reaction cells under simultaneous and individual excitation conditions.

[0049] Figure 24 This represents the relationship between hydrogen peroxide concentration and ECL luminescence intensity in the first reaction cell under different excitation devices.

[0050] Figure 25 This represents the relationship between hydrogen peroxide concentration and ECL luminescence intensity in the second reaction cell under different excitation devices.

[0051] Figure 26 The effect of the driving voltage provided to the constant potential excitation device on the luminous intensity of ECL.

[0052] Figure 27 The graph shows the linear fit between Ru(bpy)32+ concentration and ECL luminescence intensity.

[0053] Figure 28 This is a schematic diagram showing whether the first and second reaction tanks are physically separated.

[0054] Figure 29 The comparison of ECL luminescence intensity when the constant potential excitation device simultaneously excites the first and second reaction cells with / without physical separation in two different reaction systems.

[0055] Explanation of icon numbers:

[0056] 1-Electrochemiluminescence chip; 11-Electrode sheet; 111-Shared counter electrode; 112-First working electrode; 113-First reference electrode; 114-Second working electrode; 115-Second reference electrode; 116-Driving electrode; 117-Central through hole; 118-Electrical contact area; 12-Sample loading sheet; 121-First reaction cell; 122-Second reaction cell; 13-Top cover; 131-First observation area; 132-Second observation area; 133-Upper opening groove; 14-Lower cover; 141-Groove; 142-Lower opening groove. Detailed Implementation

[0057] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the present invention's five-channel three-electrode electrochemiluminescence detector.

[0058] Please see Figure 1 and Figure 2 This utility model discloses a five-channel three-electrode electrochemiluminescence detector, including an electrochemiluminescence chip 1 and a five-channel three-electrode electrochemiluminescence constant potential excitation device. The electrochemiluminescence chip 1 includes an electrode sheet 11, a sample application sheet 12, an upper cover 13, and a lower cover 14, with the electrode sheet 11 and sample application sheet 12 disposed between the upper cover 13 and the lower cover 14. The front of the electrode sheet 11 has a shared counter electrode 111, a first working electrode 112, a first reference electrode 113, a second working electrode 114, and a second reference electrode 115. The back of the electrode sheet 11 has a driving electrode 116 for the shared counter electrode 111. The shared counter electrode 111 and the driving electrode 116 are physically connected through a central through-hole 117. The sample application sheet 12 covers the shared counter electrode 111, the first working electrode 112, the first reference electrode 113, the second working electrode 114, and the second reference electrode 115.

[0059] Please see Figure 1 and Figure 2 The bottom ends of the first working electrode 112, the first reference electrode 113, the second working electrode 114, the second reference electrode 115, and the bottom end of the driving electrode 116 form an electrical contact area 118. The first side of the counter electrode 111, the first side of the sample patch 12 corresponding to the first working electrode 112 and the first reference electrode 113 form a first reaction cell 121. The second side of the counter electrode 111, the second side of the sample patch 12 corresponding to the second working electrode 114 and the second reference electrode 115 form a second reaction cell 122. The constant potential excitation device is connected to the electrical contact area 118 to excite the first reaction cell 121 and the second reaction cell 122 to produce an electrochemiluminescence reaction.

[0060] Please see Figure 2 , Figure 3 and Figure 4 Electrode 11 is a transparent PET plastic sheet constructed from conductive carbon ink through screen printing. The central through-hole 117 on electrode 11 is cut using a laser cutter. During screen printing of electrode 11, carbon ink permeates through the central through-hole 117, thus physically connecting the shared counter electrode 111 and drive electrode 116. Sample 12 is prepared by cutting non-woven fabric using a laser cutter. Both the upper cover 13 and the lower cover 14 are manufactured using 3D printing technology. The upper cover 13 has a first observation area 131, a second observation area 132, and an upper opening groove 133; the lower cover 14 has a groove 141 and a lower opening groove 142. The upper opening groove 133 of the upper cover 13 and the lower opening groove 142 of the lower cover 14 are used for electrical connection between the electrical contact area 118 and the constant potential excitation device.

[0061] The constant potential excitation device includes a power supply unit, a constant potential circuit, an external interface circuit, a WiFi circuit, a control unit, a relay circuit, an OLED display, a reset circuit, a serial port circuit, a signal generation circuit, and a button circuit integrated on a circuit board. The constant potential circuit, external interface circuit, WiFi circuit, control unit, relay circuit, OLED display, reset circuit, serial port circuit, signal generation circuit, and button circuit are respectively connected to the power supply unit. The constant potential circuit, external interface circuit, WiFi circuit, relay circuit, OLED display, reset circuit, serial port circuit, signal generation circuit, and button circuit are respectively connected to the control unit. The signal generation circuit is connected to the constant potential circuit. The power supply unit is connected to an external power supply. The WiFi circuit is connected to a host computer.

[0062] like Figure 5As shown, the power supply unit includes a +5V to +3.3V buck converter, a +5V to +12V boost converter, a +5V to -12V buck converter, a +12V to +5V buck converter, and a +12V to +5.21V buck converter. The +5V to +3.3V buck converter provides power to the control unit, relay circuit, signal generation circuit, OLED display, serial port circuit, and WiFi circuit. The +5V to +12V boost converter provides power to the signal generation circuit and the constant potential circuit, and also provides power to the +12V to +5V buck converter and the +12V to +5.21V buck converter. The +5V to -12V buck converter provides power to the signal generation circuit and the constant potential circuit, while the +12V to +5V buck converter and the +12V to +5.21V buck converter provide power to the signal generation circuit.

[0063] like Figure 6 As shown, the +5V to +3.3V step-down circuit uses an AMS1117-3.3 linear regulator chip to convert the external +5V power supply to +3.3V. The +3.3V voltage is used to drive the indicator light to show the circuit's operating status through a 4.7KΩ resistor for current limiting. The circuit is equipped with 22μF and 100nF decoupling capacitors for filtering and stabilizing the power supply, reducing voltage fluctuations and high-frequency noise, and ensuring stable circuit operation.

[0064] like Figure 7 As shown, the +5V to +12V boost converter uses an MT3608 DC-DC converter chip to boost the external +5V power supply. The boosted voltage signal is then converted into a high-precision, low-ripple +12V output signal using a 78L12 linear regulator. A 0Ω resistor further isolates the +12V output signal into an analog +12V voltage signal and a digital +12V voltage signal. The analog +12V voltage signal provides a low-noise positive voltage power supply for the signal generation circuit and the constant potential circuit. The digital +12V voltage signal provides a positive voltage power supply for the +12V to +5V buck converter and the +12V to +5.21V buck converter. An inductor is configured in the boost converter to store energy and release it during switching cycles to increase the output voltage. Schottky diodes are included to prevent reverse current flow and provide a current path during switching cycles.

[0065] like Figure 8 As shown, the +5V to -12V step-down circuit converts the external +5V power supply into a negative voltage signal through an asynchronous step-down converter HT7463A. The negative voltage signal is then converted into a high-precision, low-ripple -12V output signal using a linear regulator 79L12. Furthermore, the -12V output signal is isolated into an analog -12V voltage signal and a digital -12V voltage signal through a 0Ω resistor. The analog -12V voltage signal provides a stable negative voltage power supply for the signal generation circuit and the constant potential circuit.

[0066] like Figure 9 As shown, the +12V to +5V step-down circuit uses the REF195GSZ voltage reference chip to convert the digital +12V voltage signal into a low-noise, highly stable 5V voltage, providing a precise regulated power supply for the signal generation circuit. Figure 10 As shown, the +12V to +5.21V step-down circuit converts the digital +12V voltage signal to +5.21V voltage through the linear regulator LM317LF. The +5.21V voltage drives the indicator LED9 to illuminate and indicate the working status of the circuit through a 10KΩ resistor for current limiting.

[0067] like Figure 11 As shown, the constant potential circuit includes a first voltage follower OPA604, an operational amplifier OP07, and a power amplifier BUF634. The first voltage follower OPA604 enhances the potential drive capability. The first voltage follower OPA604 maintains a constant potential between the first reference electrode and the first working electrode. The second voltage follower OPA604 maintains a constant potential between the second reference electrode and the second working electrode. The operational amplifier OP07 provides an excitation signal to the shared counter electrode, and the power amplifier BUF634 amplifies the excitation signal output from the operational amplifier OP07 again, solving the problem of insufficient excitation current caused by the first and second reaction cells sharing a common counter electrode. To effectively overcome interference in the circuit and ensure impedance matching in the linear circuit, the constant potential circuit uses parallel reverse diodes to prevent components from being damaged by overvoltage and overcurrent.

[0068] like Figure 12 As shown, the external interface circuit includes a +3.3V interface, a +12V interface, a -12V interface, a +5V interface, a +5.21V interface, a shared counter electrode interface, a first working electrode interface, a first reference electrode interface, a second working electrode interface, and a second reference electrode interface. The +3.3V interface is connected to the output of the +5V to +3.3V buck converter circuit; the +12V interface is connected to the output of the +5V to +12V boost converter circuit; the -12V interface is connected to the output of the +5V to -12V buck converter circuit; the +5V interface is connected to the output of the +12V to +5V buck converter circuit; and the +5.21V interface is connected to the output of the +12V to +5.21V buck converter circuit. The shared counter electrode interface, the first working electrode interface, the first reference electrode interface, the second working electrode interface, and the second reference electrode interface are respectively connected to the drive electrode, the first working electrode, the first reference electrode, the second working electrode, and the second reference electrode.

[0069] like Figure 13As shown, the WiFi circuit communicates wirelessly with the host computer via the TCP protocol. The WiFi circuit obtains data from the host computer and transmits the data to the control unit via USART2 to control the voltage of the constant potential circuit.

[0070] like Figure 14 As shown, the control unit includes an STM32F103CBT6 chip, a clock circuit, a startup circuit, and a decoupling circuit. The STM32F103CBT6 chip is connected to the clock circuit, startup circuit, and decoupling circuit. The clock circuit uses a crystal oscillator to provide the operating clock signal to the STM32F103CBT6 chip. Capacitors connected across the crystal oscillator filter and eliminate inductive interference. The startup circuit uses a header pin connected in series with resistors to the BOOT0 and BOOT1 pins of the STM32F103CBT6 chip. The decoupling circuit uses multiple capacitors to connect the 3.3V supply voltage to the ground of the STM32F103CBT6 chip. These capacitors are placed close to the STM32F103CBT6 chip to reduce noise and interference on the power line.

[0071] like Figure 15 As shown, the relay circuit uses NPN transistors and PNP transistors as switches; the control unit releases a voltage signal to control the switch to turn off, thereby manipulating the armature in the relay to engage and disengage, thus individually controlling the conduction and disengagement of the excitation signal of the shared counter electrode, so that the constant potential excitation device is first connected to the first reference electrode, the second reference electrode, the first working electrode, and the second working electrode of the electrochemiluminescence chip, and then connected to the shared counter electrode.

[0072] like Figure 16 As shown, the OLED display communicates with the control unit via the I2C protocol. The OLED display shows the status of the constant potential excitation device and the magnitude of the excitation voltage. Figure 17 As shown, the reset circuit includes a reset button, a resistor, and a capacitor. It adopts a low-level reset method. When the reset button is pressed during the operation of the control unit, the reset pin in the reset circuit is directly connected to GND, the capacitor discharges and the control unit is reset. After the reset button is released, the capacitor continues to charge. After a few milliseconds, the charging is completed, the reset circuit is disconnected, and the control unit enters the working state.

[0073] like Figure 18 As shown, the serial port circuit uses a USB to TTL serial port chip as its core, and is equipped with a crystal oscillator and filter capacitors. In the USB interface, CH340 D+ and CH340 D- are connected to UD+ and UD- of the serial port chip. The serial port chip then sends the data to the STM32F103CBT6 chip through RXT and TXD, thereby ensuring that the external program is safely burned into the control unit.

[0074] like Figure 19As shown, the signal generation circuit includes a 16-bit digital-to-analog converter chip DAC8831 and a low-noise, low-temperature-drift, high-precision operational amplifier OPA277. The DAC8831 and OPA277 convert the digital signal output from the microcontroller into an analog signal and send it to the constant-potential circuit. The DAC8831 communicates with the control unit via the SPI protocol. The OPA277, in conjunction with the DAC8831, enhances the output drive capability of the DAC8831, thereby providing a precise voltage signal to the constant-potential circuit.

[0075] like Figure 20 As shown, the button circuit is connected to the control unit via DuPont wires. It can not only select different excitation voltages but also control the on / off state of the excitation signal. The host computer communicates remotely with the control unit via WiFi, enabling wireless control of the circuit board. The timing current method parameters can be set via the host computer, making operation simple.

[0076] Application Example 1

[0077] This application example uses a five-channel three-electrode electrochemiluminescence detector to quantitatively detect hydrogen peroxide in a luminol / hydrogen peroxide system.

[0078] (1) The pH of distilled water was adjusted to 10 using NaOH solution (0.1 M) to prepare 5 mM luminol solution. Hydrogen peroxide solutions with concentrations of 2 mM, 4 mM, 6 mM, 8 mM and 10 mM were prepared using distilled water. The hydrogen peroxide solutions of different concentrations were mixed with 5 mM luminol solution at a volume ratio of 1:1 to obtain the test solution.

[0079] (2) Use a pipette to add 35 µL of the test liquid to the first reaction cell and the second reaction cell, press the upper cover and the lower cover tightly to close them, and assemble them into an electrochemiluminescence chip.

[0080] (3) Using the chronoamperometry method, a 2.5 V excitation voltage was applied to the electrochemiluminescence chip through the constant potential excitation device of the five-channel three-electrode electrochemiluminescence detector. After the five-channel three-electrode electrochemiluminescence detector finished its detection, the electrochemiluminescence imaging data was further analyzed and processed using Origin software.

[0081] (4) The results are as follows Figure 21As shown in the figure, it can be seen that with the constant potential excitation device of this invention, the electrochemiluminescence intensity in the first and second reaction cells increases accordingly with the increase of hydrogen peroxide concentration, showing a good linear relationship between hydrogen peroxide concentration and electrochemiluminescence intensity. For the first reaction cell, the linear fitting equation is Y = 7.3574X + 1.8585 (RA² = 0.9907, n = 5). For the second reaction cell, the linear fitting equation is Y = 7.3919X + 1.8434 (RB² = 0.9841, n = 5). Therefore, the five-channel three-electrode electrochemiluminescence detector of this invention has the potential for quantitative detection of hydrogen peroxide.

[0082] Application Example 2

[0083] This application example uses a five-channel three-electrode electrochemiluminescence detector to verify whether the first and second reaction cells can independently and quantitatively detect hydrogen peroxide in the luminol / hydrogen peroxide system.

[0084] (1) The test solution used is similar to that in Example 2.

[0085] (2) such as Figure 22 As shown in (A), 35 µL of the test solution was added to the first and second reaction cells using a pipette. The upper and lower covers were then pressed tightly together to assemble the electrochemiluminescence chip. Figure 22 As shown in (B), the sample patch covers only the first or second reaction cell, into which 17 µL of the test solution is added. The upper and lower covers are pressed tightly to close the chip, and the chip is assembled into an electrochemiluminescence chip. The first or second reaction cell is excited separately.

[0086] (3) The detection process is similar to that in Application Example 1, and the results are as follows: Figure 23 As shown.

[0087] As shown in the figure, for each hydrogen peroxide concentration, there was no significant difference in the electrochemiluminescence intensity caused by simultaneous excitation of the first reaction cell and that caused by individual excitation of the first reaction cell; similarly, there was no significant difference in the electrochemiluminescence intensity caused by simultaneous excitation of the second reaction cell and that caused by individual excitation of the second reaction cell. These results indicate that under simultaneous excitation conditions, the two reaction cells on the electrochemiluminescence chip are independent and do not interfere with each other.

[0088] Application Example 3

[0089] Based on Application Example 2, this application example uses a constant potential excitation device and a traditional potentiostat to conduct a comparative experiment on electrochemiluminescence.

[0090] (1) The pH of distilled water was adjusted to 10 using NaOH solution (0.1 M) to prepare 5 mM luminol solution. Hydrogen peroxide solutions with concentrations of 1 mM, 2 mM, 3 mM and 4 mM were prepared using distilled water. The hydrogen peroxide solutions of different concentrations were mixed with 5 mM luminol solution at a volume ratio of 1:1 to obtain the test solution.

[0091] (2) The assembly method and detection process of the electrochemiluminescence chip are similar to those in Application Example 1, and the results are as follows: Figure 24 and Figure 25 As shown in the figure, it can be seen that as the concentration of hydrogen peroxide in the test solution increases, the electrochemiluminescence intensity triggered by the constant potential excitation device and the traditional potentiostat exhibit the same trend and detection effect. This indicates that the constant potential excitation device of this invention has good application potential in electrochemiluminescence detection.

[0092] Application Example 4

[0093] This application example uses a five-channel three-electrode electrochemiluminescence detector to investigate the effect of different driving voltages provided by the constant potential excitation device on the electrochemiluminescence intensity in a luminol / hydrogen peroxide system.

[0094] (1) The pH of distilled water was adjusted to 10 using NaOH solution (0.1 M) to prepare 5 mM luminol solution. 1 mM hydrogen peroxide solution was prepared using distilled water. 1 mM hydrogen peroxide solution and 5 mM luminol solution were mixed in a 1:1 volume ratio to obtain the test solution.

[0095] (2) The driving voltage provided by the electrochemiluminescence constant potential excitation device of the five-channel three-electrode electrochemiluminescence detector is set to 2.5 V, 2.75 V, 3.0 V, 3.5 V, 4.0 V and 4.5 V.

[0096] (3) The chip assembly method and testing process are similar to those in Example 2, and the results are as follows: Figure 26 As shown in the figure, it can be seen that as the driving voltage increases from 2.5 V to 4.5 V, the electrochemiluminescence intensity of the first reaction cell increases from 0.70 × 10⁵ to 35.13 × 10⁵, and the electrochemiluminescence intensity of the second reaction cell increases from 0.72 × 10⁵ to 35.80 × 10⁵. Therefore, the electrochemiluminescence chip of this invention can be well triggered by different driving voltages provided by a constant potential excitation device.

[0097] Application Example 5

[0098] This application example uses a five-channel three-electrode electrochemiluminescence detector to detect different concentrations of Ru(bpy)32+ in a ruthenium terpyridine / tripropylamine (Ru(bpy)32+ / TPA) system.

[0099] (1) Prepare Ru(bpy)32+ solutions with concentrations of 0.1mM, 0.5mM, 2.5mM and 5mM using PBS solution (10×). Mix the Ru(bpy)32+ solutions of different concentrations with TPA solution (obtained by diluting 98% TPA with PBS (pH 7.4)) at a volume ratio of 1:1 to obtain the test solution; the excitation voltage provided by the constant potential excitation device is 3 V.

[0100] (2) The assembly method and detection process of the electrochemiluminescence chip are similar to those in Application Example 1, and the results are as follows: Figure 27 As shown in the figure, the five-channel three-electrode electrochemiluminescence detector of this invention exhibits a good linear relationship between Ru(bpy)32+ concentration and electrochemiluminescence intensity in both the first and second reaction cells as the Ru(bpy)32+ concentration increases. For the first reaction cell, the linear fitting equation is Y = 9.8559X + 0.3548 (RA2 = 0.9878, n = 5). For the second reaction cell, the linear fitting equation is Y = 9.5298X + 0.2767 (RB2 = 0.9863, n = 5). Therefore, the five-channel three-electrode electrochemiluminescence detector of this invention has the potential for quantitative detection of Ru(bpy)32+.

[0101] Application Example 6

[0102] This application example uses a five-channel three-electrode electrochemiluminescence detector to verify the feasibility of different systems of electrochemiluminescence reactions in different reaction cells on the electrochemiluminescence chip under different systems of luminol / hydrogen peroxide and Ru(bpy)32+ / TPA. This verifies the potential of simultaneously performing quantitative detection of analytes in different reaction systems on a single electrochemiluminescence chip.

[0103] (1) A 5 mM Ru(bpy)32+ solution was prepared using PBS solution (10×), and mixed with TPA solution at a 1:1 volume ratio to obtain the Ru(bpy)32+ / TPA system test solution; the pH of distilled water was adjusted to 10 using NaOH solution (0.1M) to prepare a 5 mM luminol solution; a 5 mM hydrogen peroxide solution was prepared using distilled water; and the 5 mM hydrogen peroxide solution and 7 mM luminol solution were mixed at a 1:1 volume ratio to obtain the luminol system test solution. The excitation voltage provided by the constant potential excitation device was 3V.

[0104] (2) such as Figure 28 As shown in (A), 35 µL of the luminol / hydrogen peroxide system or the Ru(bpy)32+ / TPA system analyte was added dropwise to the first and second reaction cells using a pipette. The upper and lower covers were then pressed tightly together to assemble the electrochemiluminescence chip. Figure 28 As shown in (B), the first reaction cell and the second reaction cell are physically separated. 17 µL of luminol / hydrogen peroxide system test solution is added to the first reaction cell, and 17 µL of Ru(bpy)32+ / TPA system test solution is added to the second reaction cell. The upper and lower covers are pressed tightly to close the cells and assembled into an electrochemiluminescence chip.

[0105] (3) The detection process of the electrochemiluminescence chip is similar to that in Application Example 1, and the results are as follows: Figure 29 As shown. Group 1 is the luminol / hydrogen peroxide system when the two reaction tanks are not physically separated; Group 2 is the Ru(bpy)32+ / TPA system when the two reaction tanks are physically separated, with the first reaction tank being the luminol / hydrogen peroxide system and the second reaction tank being the Ru(bpy)32+ / TPA system; Group 3 is the Ru(bpy)32+ / TPA system when the two reaction tanks are not physically separated.

[0106] As shown in the figure, in the luminol / hydrogen peroxide system, there is no significant difference in electrochemiluminescence intensity between the first reaction cell when the two reaction cells are not physically separated and the first reaction cell when the two reaction cells are physically separated; similarly, in the Ru(bpy)32+ / TPA system, there is no significant difference in electrochemiluminescence intensity between the second reaction cell when the two reaction cells are not physically separated and the second reaction cell when the two reaction cells are physically separated. These results indicate that the five-channel three-electrode electrochemiluminescence detector of this invention has good application potential for simultaneously detecting different electrochemiluminescence systems.

[0107] The above description is a detailed description of preferred embodiments, but the embodiments are not intended to limit the scope of the patent application. Any equivalent changes or modifications made under the disclosed technical spirit should fall within the scope of the patent.

Claims

1. A five-channel three-electrode electrochemiluminescence detector, characterized in that, The device includes an electrochemiluminescence chip and a constant potential excitation device. The electrochemiluminescence chip includes an electrode sheet, a sample application sheet, an upper cover, and a lower cover. The electrode sheet and the sample application sheet are disposed between the upper cover and the lower cover. The front side of the electrode sheet is provided with a shared counter electrode, a first working electrode, a first reference electrode, a second working electrode, and a second reference electrode. The back side of the electrode sheet is provided with a driving electrode for the shared counter electrode. The shared counter electrode is connected to the driving electrode. The sample application sheet covers the shared counter electrode, the first working electrode, the first reference electrode, the second working electrode, and the second reference electrode. The bottom ends of the first working electrode, the first reference electrode, the second working electrode, the second reference electrode, and the driving electrode serve as electrical contact areas. They share the first side of the counter electrode, the first side of the sample application sheet corresponding to the first working electrode and the first reference electrode to form a first reaction cell. They share the second side of the counter electrode, the second side of the sample application sheet corresponding to the second working electrode and the second reference electrode to form a second reaction cell. A constant potential excitation device is connected to the electrical contact areas to excite the first and second reaction cells to produce an electrochemiluminescence reaction. The constant potential excitation device includes a power supply unit, a constant potential circuit, an external interface circuit, a WiFi circuit, a control unit, a relay circuit, an OLED display, a reset circuit, a serial port circuit, a signal generation circuit, and a button circuit integrated on a circuit board. The constant potential circuit, external interface circuit, WiFi circuit, control unit, relay circuit, OLED display, reset circuit, serial port circuit, signal generation circuit, and button circuit are respectively connected to the power supply unit. The constant potential circuit, external interface circuit, WiFi circuit, relay circuit, OLED display, reset circuit, serial port circuit, signal generation circuit, and button circuit are respectively connected to the control unit. The signal generation circuit is connected to the constant potential circuit. The power supply unit is connected to an external power supply.

2. The five-channel three-electrode electrochemiluminescence detector according to claim 1, characterized in that, The power supply unit includes a +5V to +3.3V step-down circuit, a +5V to +12V boost circuit, a +5V to -12V step-down circuit, a +12V to +5V step-down circuit, and a +12V to +5.21V step-down circuit. The +5V to +3.3V step-down circuit provides power to the control unit, relay circuit, signal generation circuit, OLED display, serial port circuit, and WiFi circuit. The +5V to +12V boost circuit provides power to the signal generation circuit and the constant potential circuit, and also provides power to the +12V to +5V buck circuit and the +12V to +5.21V buck circuit; the +5V to -12V buck circuit provides power to the signal generation circuit and the constant potential circuit, and the +12V to +5V buck circuit and the +12V to +5.21V buck circuit provide power to the signal generation circuit.

3. The five-channel three-electrode electrochemiluminescence detector according to claim 2, characterized in that, The +5V to +3.3V step-down circuit uses an AMS1117-3.3 linear regulator chip to convert the external +5V power supply to +3.3V. The +3.3V voltage is limited by a 4.7KΩ resistor to drive the indicator light to show the circuit's operating status. The circuit is equipped with 22μF and 100nF decoupling capacitors for filtering.

4. The five-channel three-electrode electrochemiluminescence detector according to claim 2, characterized in that, The +5V to +12V boost circuit uses the MT3608 DC-DC converter chip to boost the external +5V power supply. The boosted voltage signal is converted into a +12V output signal by a 78L12 linear regulator. The +12V output signal is isolated into an analog +12V voltage signal and a digital +12V voltage signal through a 0Ω resistor. The analog +12V voltage signal provides positive power to the signal generation circuit and the constant potential circuit, while the digital +12V voltage signal provides positive power to the +12V to +5V buck circuit and the +12V to +5.21V buck circuit. The +5V to -12V step-down circuit uses an asynchronous step-down converter HT7463A to convert the external +5V power supply into a negative voltage signal. The negative voltage signal is then converted into a -12V output signal using a linear regulator 79L12. The -12V output signal is isolated into an analog -12V voltage signal and a digital -12V voltage signal through a 0Ω resistor. The analog -12V voltage signal provides negative power to the signal generation circuit and the constant potential circuit.

5. The five-channel three-electrode electrochemiluminescence detector according to claim 4, characterized in that, The +12V to +5V step-down circuit converts the digital +12V voltage signal into a 5V voltage through the REF195GSZ voltage reference chip, providing a regulated power supply for the signal generation circuit. The +12V to +5.21V step-down circuit uses a linear regulator LM317LF to convert the digital +12V voltage signal to +5.21V. The +5.21V voltage drives the LED9 indicator light to illuminate and indicate the circuit's operating status through a 10KΩ resistor for current limiting.

6. The five-channel three-electrode electrochemiluminescence detector according to claim 2, characterized in that, The external interface circuit includes a +3.3V interface, a +12V interface, a -12V interface, a +5V interface, a +5.21V interface, a shared counter electrode interface, a first working electrode interface, a first reference electrode interface, a second working electrode interface, and a second reference electrode interface. The +3.3V interface is connected to the output of the +5V to +3.3V step-down circuit; the +12V interface is connected to the output of the +5V to +12V boost circuit; the -12V interface is connected to the output of the +5V to -12V step-down circuit; the +5V interface is connected to the output of the +12V to +5V step-down circuit; and the +5.21V interface is connected to the output of the +12V to +5.21V step-down circuit. The shared counter electrode interface, first working electrode interface, first reference electrode interface, second working electrode interface, and second reference electrode interface are respectively connected to the drive electrode, first working electrode, first reference electrode, second working electrode, and second reference electrode.

7. The five-channel three-electrode electrochemiluminescence detector according to claim 1, characterized in that, The constant potential circuit includes two voltage followers OPA604, an operational amplifier OP07, and a power amplifier BUF634. The two voltage followers OPA604 are used to maintain a constant potential between the first reference electrode and the first working electrode or between the second reference electrode and the second working electrode. The operational amplifier OP07 provides an excitation signal for the shared counter electrode. The power amplifier BUF634 amplifies the excitation signal output by the operational amplifier OP07 again.

8. The five-channel three-electrode electrochemiluminescence detector according to claim 1, characterized in that, The control unit includes an STM32F103CBT6 chip, a clock circuit, a startup circuit, and a decoupling circuit. The clock circuit uses a crystal oscillator to provide the running clock signal to the STM32F103CBT6 chip, and capacitors are connected across the two ends of the crystal oscillator for filtering. The startup circuit uses a header pin connected in series with resistors to the BOOT0 and BOOT1 pins of the STM32F103CBT6 chip. The decoupling circuit uses multiple capacitors to connect the 3.3V supply voltage to the ground terminal of the STM32F103CBT6 chip.

9. The five-channel three-electrode electrochemiluminescence detector according to claim 1, characterized in that, The serial port circuit uses a USB to TTL serial port chip, the reset circuit uses a low-level reset method, the relay circuit uses NPN transistors and PNP transistors as switches, and the OLED display is used to display the status of the constant potential excitation device and the excitation voltage value.

10. The five-channel three-electrode electrochemiluminescence detector according to claim 1, characterized in that, The signal generation circuit includes a digital-to-analog converter chip DAC8831 and an operational amplifier OPA277. The digital signal output by the microcontroller is converted into an analog signal by the digital-to-analog converter chip DAC8831 and the operational amplifier OPA277 and then sent to the constant potential circuit.

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